Generally, when an opening into a substrate is desired, the substrate may be initially masked by either a photoresist, hard mask, or other mask to protect those areas of the substrate where an opening is not desired. Once those areas are protected, the exposed portions of the substrate may be exposed to an etchant in order to react and remove the exposed material of the substrate to form the opening. Once the etchant has reacted with the material of the substrate and formed the opening to a desired depth, the etchant may be removed from the substrate, and other various processes may be utilized as desired in order to continue the manufacturing of the semiconductor device on the substrate.
In the etching process, a wet etch may be utilized in which the substrate is coated with the desired etchant in a liquid phase (instead of a vapor phase). The desired liquid etchant may be supplied from an etchant canister to an etching chamber, where a showerhead may then be used to disperse the etchant evenly across the substrate such that the desired liquid etchant is in contact with the exposed portions of the substrate. Once in contact with the exposed portions of the substrate, the etchant will begin to react with the substrate to form the desired opening where the masks do not protect the substrate.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.